What term describes a change in the electrical state of a neuron that decreases the likelihood of firing an action potential?

The correct term that describes a change in the electrical state of a neuron that decreases the likelihood of firing an action potential is hyperpolarization. Hyperpolarization refers to an increase in the negative charge inside the neuron, moving the membrane potential farther from the threshold needed to trigger an action potential. This occurs when potassium channels open, allowing more positive ions to exit the cell or when chloride ions enter the cell, resulting in a less excitable state.

Inhibition, while related to the process of hyperpolarization, refers more generally to the action that reduces the activity of a neuron rather than specifying the exact electrical state changes that lead to decreased excitability. The other terms, including depolarization and excitation, actually involve changes that make an action potential more likely to occur, which is the opposite of what is described in the question. Understanding these concepts is essential for grasping how neurons communicate and how different neurochemical signals can impact neuronal firing.